Many historic and architecturally significant buildings have plaster ceilings, many of which have delicate painted or applied decorations. In many of these buildings, over time, the plaster becomes structurally compromised as the mechanical keys that physically hold the plaster onto the lath break. In some cases, the plaster begins to pull away from the lath and starts to sag or fall.
Conservation and restoration work aims to preserve plaster ceilings that are in danger of sagging or falling. In the course of doing the conservation work, the plaster must be prevented from falling or further sagging during the conservation treatments. In some cases in the past, plaster ceilings have been supported during conservation work with crude props. For example, a flat padded board, such as plywood with a felt or cotton padding on one side, may be pressed against the plaster ceiling and held in place with one or more stout wooden props. This is sometimes termed a “deadman”. In some cases, instead of a prop the padded board may be held in place with spring-loaded or telescoping poles.
These crude conventional mechanisms for supporting plaster ceilings have disadvantages. A large padded board obscures from view the very plaster ceiling that is the subject of the conservation effort. The props and spring-loaded posts are only crudely adjustable and can apply excessive pressure against the damaged plaster, thereby resulting in additional damage. In some cases, the additional damage results in the collapse of the ceiling when the temporary support is removed.
Many ceilings in historic buildings are at a significant height. In cases where a network of props or posts are used to support such a ceiling, it can be very difficult to install the scaffolding necessary for workers to engage in the conservation work. Moreover, some excessively long props or posts are too flexible to provide secure support.
In some instances, scaffolding may be installed prior to installation of ceiling supports. In these cases, posts or props may be put in place that are supported by the working surface of the scaffolding. However, workers walking on the working surface cause deflections in the scaffolding floor that are transferred directly to the posts or props and, thus, to the padded board supporting the ceiling. These deflections can cause additional damage to the plaster.
It would be advantageous to provide for another method and device for supporting plaster ceilings.
Similar reference numerals may have been used in different figures to denote similar components.